USPTO Patents Application 10772371

WHAT IS CLAIMED IS:

1. An image forming method for forming an image by
supplying a developer from a development unit to a latent

5 image on a latent image carrying member for image development,
the method comprising the steps of:

forming a thin layer of developer on a developer
carrying member by generating an electric field in a
developer supply zone between the developer carrying member
10 of the development unit and a developer conveyance member;
and

conveying the thin layer of developer formed on the
developer carrying member to a development zone facing the
latent image carrying member.

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2. An image forming method according Claim 1, wherein
the developer image is developed from the latent image by
putting the thin layer of developer formed on the developer
carrying member into contact with the latent image carrying

2 0 member to develop an image from the latent image.

3. An image forming method according to Claim 1,
wherein the developer image is developed from the latent
image by generating an alternating electric field in the

25 development zone to supply the thin layer of developer on the

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developer carrying member to the latent image carrying member
in a non-contact manner.

4. An image forming method according to Claim 1,

5 wherein the developer conveyance member conveys the developer
using electrostatic effect to supply the developer to the
developer carrying member.

5. An image forming method according to Claim 1,

10 wherein the developer is charged by a friction taking place
between the developer conveyance member and the developer
when the developer is conveyed by the developer conveyance
member .

15 6-. An image forming method according to Claim 5,

wherein a protective layer made of a silicone-based resin is
disposed on the surface of the developer conveyance member.

7. An image forming method according to Claim 4,
20 wherein a relationship of |Vs|>|Vd| holds where Vd represents
a surface movement velocity of the developer carrying member,
and Vs represents a developer conveyance velocity of the
developer moving on the developer conveyance member.

25 8 . An image forming method according to Claim 1,

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wherein an alternating field is generated between the
developer carrying member and the developer conveyance member,
both of which are arranged to be out of contact from each
other -

5

9, An image forming method according to Claim 1,
wherein a powder pump supplies the developer to the developer
conveyance member from a developer container.

10 10. An image forming method according to Claim 1,

wherein recovery means for recovering the developer on the
developer carrying member is arranged downstream of the
development zone and upstream of the developer supply zone
along the surface movement direction of the developer

15 carrying member.

11. An image forming method according to Claim 1,
wherein developer charge amount changing means for changing
the amount of charge of the developer on the developer

20 carrying member is arranged downstream of the development '
zone and upstream of the developer supply zone along the
surface movement direction of the developer carrying member.

12. An image forming method according to Claim 1,
25 wherein an electrically conductive member for applying a

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voltage to the developer on the developer carrying member is
arranged downstream of the development zone and upstream of
the developer supply zone along the surface movement
direction of the developer carrying member.

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13. An image forming method according to Claim 1,
wherein a toner having a spherical shape is used as the
developer .

10 14. An image forming method according to Claim 13,

wherein the toner has a sphericity of 0.96 or larger.

15. An image forming method according to Claim 1,
wherein a relationship of P/{ (Vd/Vp) (Vs/Vd)}<20 |iim holds and

15 a surface movement of the developer carrying member is

aligned in the same direction as a surface movement of the
latent image carrying member in the development zone, where P
represents a pitch of electrodes in the developer conveyance
member, Vs represents a developer conveyance velocity of the

20 developer moved by the developer conveyance member, Vd
represents a surface movement velocity of the developer
carrying member, and Vp represents a surface movement
velocity of the latent image carrying member.

25 16. An image forming apparatus for forming an image by

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supplying a developer from a development unit to a latent
image on a latent image carrying member for image development,

wherein the image forming apparatus forms the image
using an image forming method according to one of Claims 1
through 15.

17. An image forming apparatus according to Claim 16,
comprising a process cartridge having the development unit
and the latent image carrying member integrated with the
development unit in a unitary body, wherein the process
cartridge is detachably mounted in the image forming
apparatus .

18. A process cartridge integrating into a unitary body
a latent image carrying member and at least a development
unit for developing a developer image from a latent image on
the latent image carrying member, wherein the process
cartridge is detachably mounted in an image forming apparatus
according to Claim 16.

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